False-twist device

ABSTRACT

False-twist device for textile yarns has circular discs arranged on parallel shafts, four such shafts being provided, opposite shafts having at the same level discs formed with configurations extending at any angle relative to the discs surfaces and with profiles of pairs of discs at the same level in mutual engagement.

United States Patent 11 1 Knebel 1 Nov. 5, 1974 FALSE-TWIST DEVICE 3,021,663 2 1962 Findlow 57 77.4 3,112,600 12/1963 Stoddard et a1. 57/77.4 X [75] lnvemors Knebel Dubendorf, 3,287,890 11/1966 McIntosh et 61 57/774 Swltzerland 3,705,488 12/1972 Sholly. Jr. et a1 57/774 [73 Assigneez Heberlein & C0. AG, Wattwil, 3,705,847 12/1972 Carruthers 57/774 Swltzerland FOREIGN PATENTS OR APPLICATIONS [22] Fi1ed: Apr. 4, 1973 1,242,321 6/1967 Germany 57/77.4 [211 App! 347673 Primary Examiner.1ohn W. Huckert Assistant ExaminerChar1es Gorenstein [30] Foreign Application Priority Data Attorney, Agent, or Firm-Fitzpatrick, Ce11a, Harper Apr. 11, 1972 Switzerland 5395 72 & Scimo [52] US. Cl. 57/77.4, 57/7745 [57] ABSTRACT d 9 False-twist device for texti1e yams has circular discs arranged on parallel shafts, four such shafts being provided, opposite shafts having at the same level discs formed with configurations extending at any angle rel- [56] References Cited ative to the discs surfaces and with profiles of pairs of UNITED STATES PATENTS discs at the same level in mutual engagement. 2,620,517 12/1952 Schlums 57/77.4 2,923,121 2 1960 Tully 57 774 9 Clams 7 Drawmg F'gures PATENTEmuv 5 m4 1845.6 1 3 sum 1 (If 2 1 FALSE-TWIST DEVICE This invention relates to false-twist devices for textile yarns, and more particularly to such devices which impart a forward movement to the yarn while falsetwisting it.

Devices for the false-twisting of textile yarns are known by means of which twist is imparted to the yarn by direct frictional contact with rotating surfaces. Thus, for example, a device is known from British Pat. specification No. 933,438 in which a number of circular discs are arranged on each of three parallel rotation shafts at certain distances so that their rims overlap, the discs being so arranged on each rotation shaft that they engage with the interstices between the discs of the other rotation shafts.

In the known false-twist devices of this type, for imparting the twist, a certain pre-tension of the yarn is necessary to press the same against the friction body. The force transmitted to the yarn by the friction body in this case acts against the direction of movement of the yarn which may cause very high differences in tension between the yarn ahead of the twist imparter and that following it. i

l have conceived a device of the class described by which I am able to eliminate the foregoing difficulty. Thus, I contribute a friction false-twist device for textile yarns with circular discs arranged on parallel rotatable shafts at certain distances and characterized in that four shafts arranged in the corners of a square are provided, and in that on the shafts situated opposite each other across the square, the discs are arranged on the same level; that furthermore, the disc rims are provided with grooves or projections extending at an ascendin g angle with respect to the disc surfaces and with profiles, and that the disc rim profiles of the two discs arranged on the same level are in mutual engagement.

There has thus been outlined rather broadly the more important features of the invention in order that thedetailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional features of the invention that will be described hereinafter and which will form the subject of the claims appended hereto. Those skilled in the art will appreciate that the conception upon which this disclosure is based may readily be utilized as a basis for the designing of other structures for carrying out the several purposes of the invention. it is important, therefore, that the claims be regarded as including such equivalent constructions as do not depart from the spirit and scope of the invention.

Specific embodiments of the invention have been chosen for purposes of illustration and description, and are shown in the accompanying drawings, forming a part of the specification wherein:

FIG. 1 is a top view of a device according to my invention;

HO. 2 is a lateral elevation of the device of FIG. 1;

FIG. 3 is a cross-sectional view taken along line A--A of FIG. 2;

FIG. 4 is a lateral elevation of two discs in the direction of arrow B of FIG. 1; and

F 168. 5A-C illustrate various embodiments of a detail of the invention.

According to FIGS. 1 and 2, a carrier plate 1, fixed in a manner not shown on the machine frame, engages with the forked recesses of two rectangular carriers 3, 4. Shafts 5, 6, 7, 8 and 9 extend through perforations in the carrier plate 1 and carriers 3 and 4 and are supported for rotation therein. The shafts 6-9 are arranged so as to lie in the corners of an imaginary square. as viewed in FIG. 1. Below the carriers 3 and 4, on the respective shafts 6, 7, 8 and 9, 1 provide pulleys ll, 12, 13 and 14; and below plate 1 on shaft 5, a pulley 15. The pulleys ll, 14 and 15 carry endless belt 16; pulleys 11 and 12 carry endless belt 17; and pulleys l3 and 14 carry endless belt 18. The shaft 5 is driven by a motor (not shown). Furthermore, the carrier 3 can be swivelled about shaft 6 and carrier 4 about shaft 9 so that the device can be opened in the way shown in FIG. 3 to permit insertion and removal of the yarn. The carriers 3 and 4 are kept together by spring 31 when the device is closed.

On each of the shafts 6, 7, 8 and 9, I provide two discs 19,20; 21,22; 23,24; 25,26; respectively, and these are separated from each other by spacers 32 which may be exchanged to vary the axial distance between discs. All the disc rims have grooves 27 extending obliquely with respect to the discs surface and having, for example, a width of 0.5 mm. and profiles which are in mutual engagement on the discs 21 and 25, 19 and 23, 33 and 26, 20 and 24 situated on the same level, as can be seen in FIG. 4.

Fine adjustment of the gap between the profiles of the disc rims according to the thickness of the yarn to be treated, can be effected by means of adjusting screws 29 and 29' which are provided in the threaded bores of the parts 30 and 30' provided on the carrier plate 1 and which act on carriers 3 and 4.

The discs are arranged on the rotatable shafts at minimum distances from each other, assuring unimpeded rotation. These distances can, depending on the thickness of the yarn to be treated, amount to between 0.2 and 1 mm. They can be adjusted by insertion of corresponding spacers between the individual discs.

The mutually engaging profiles of the rims of the discs situated on the same level and the small mutual distances between the discs in axial direction, cause the passing yarn to be pinched without a possibility of escaping, whereby twist imparting is effected practically without slippage. The oblique grooves 27 at the same time contribute a forward movement to the yarn in its advancing direction.

The grooves 27 may, for example, extend at an angle a of the order of 30 i 5 with respect to the disc surface. lt has proven advantageous successively slightly to increase the angle a of the grooves from the uppermost to the lowermost disc if the yarn moves downwards and the discs rotate counterclockwise as viewed in FIG. 1, i.e., the angle may, for example, be 30 on discs 21 and 25; 3l on discs 19 and 23; 32 on discs 22 and 26; and 33 on discs 20 and 24. In this case, the biggest angle provides the highest yarn advance rate, and the described escalation of the angles contributes to avoid yarn accumulation between the discs. Instead of obliquely extending grooves, the disc rims may also carry corresponding projections. Furthermore, the grooves or projections may be of the same width as their mutual distances. The angle a furthermore depends on the friction coefficient of the disc material and may even amount to more than 35.

4 3,845,613 3 4 The mutually engaging profiles of the disc rims may discs arranged on parallel rotatable shafts, characteralso be of other shape than as shown in FIGS. 2 and 4, ized in that four such shafts (6,7,8,9) are provided the such, for example, as the shapes 40,40; 41,41; and axes ofwhich are at the corners ofan imaginary square, 42,42 shown in FIGS. SA-C. and in that on the shafts (6,8; 7,9) situated diagonally The discs may consist of a material having high wear 5 opposite each other, the discs (19,20,23,24; resistance and, at the same time, a friction coefficient 21,22,25,26) ar arranged on the same level, the disc with respect to synthetic yarn material such as olyamjrims being provided with configurations (27) extending ides or polyester as high as possible and may, for examat an ascending angle a with respect to the disc surfaces ple, consist of metal oxide ceramic material or alumia d with r fil (40,40; 41,41; 42,42) and that the hum discs y be Provided at least on the rhhS With a jdlSC rim profiles of discs arranged on the same level are oxide coating. It is furthermore possible to use discs of l li m hard-chromed aluminum.

The primary advantage of the device according to the present invention, consists in that the ratio between yarn tensions, before entering into and after leaving the twist imparter formed by the discs, is relatively small; and in that at the same time an important advance movement in its direction of movement is imparted to the yarn.

This progressive effect is provided by means of the comparative examples described hereinafter.

the discs are arranged on the rotatable shafts in immediate proximity to one another consistent with unimeededt n- 3. Device according to claim 2, characterized in that the axial disc distances are adjustable by means of exh ebl spa e etztdi snt a i lengths V 4. Device according to claim 1, characterized in that the ascending angle a of the grooves or projections in- Two multifilamem yams of polyamide 66 (poly hexa creases by between 1 and 3 for each subsequent dlSC methylene adipamide) of various titers were subjected m dlrect-lon of m to a false-twisting treatment using a model (I) ofthe dea Devlc? accordmg to Chum chawcterlzcq m that vice of the present invention. For comparison, the false the alscendmg angle i ogrooves or Projectlohs twist was furthermore imparted by two models with (27) ofthe Order of i 5 similar arrangement of the discs, one of the models (ll) Pevlce accofdihg to Claim 1, chilrijlcterileq in that having profiles on the rims, but no grooves or projecthe dlscsconsist of metal ox de ceramic material. tions, and the other model (lll) having straight disc 7. Device accordmg to claim l,characterized m that rims but grooves. The results shown in the following 30 the al h num and are provided at least table illustrate that only when using discs, the rims of 9h W an OXldc Coatingwhich have profiles and grooves or projections, is the 8. Device according to claim 1, characterized by two described effect obtained. lcarriers each supporting a pair of adjacent shafts TABLE Twist lmparter Model I Model ll Model [I] Yarn titer dtex 78/23 156/46 78/23 l56/46 78/23 156/46 Disc circumferential speed in 345 345 345 345 345 345 m/min.

Yarn delivery speed in m/min. 100 I00 I00 I00 100 lOO Yarn tension before twist im- 7 l5 3 3 3 3 parter p Yarn tension after twist I2 24 26 20 24 27 imparter p I believe that the construction and operation of my (6,7; 8,9), at least one of said carriers being arranged novel false-twist device will now be understood, and to pivot relatively to the other of said carriers. that its advantages will be fully appreciated by those 5 9. Device according to claim 8, characterized in that persons skilled in the art. said one carrier is pivotable about the axis of one of the l claim: Q shafts supported by it.

l false-twist device forlextile yarn with circular 2. Device according to claim 1, characterized in that 

1. False-twist device for textile yarn with circular discs arranged on parallel rotatable shafts, characterized in that four such shafts (6,7,8,9) are provided the axes of which are at the corners of an imaginary square, and in that on the shafts (6,8; 7,9) situated diagonally opposite each other, the discs (19,20,23,24; 21,22,25,26) are arranged on the same level, the disc rims being provided with configurations (27) extending at an ascending angle Alpha with respect to the disc surfaces and with profiles (40,40''; 41,41''; 42,42'') and that the disc rim profiles of discs arranged on the same level are complimentary.
 2. Device according to claim 1, characterized in that the discs are arranged on the rotatable shafts in immediate proximity to one another consistent with unimpeded rotation.
 3. Device according to claim 2, characterized in that the axial disc distances are adjustable by means of exchangeable spacers of different axial lengths.
 4. Device according to claim 1, characterized in that the ascending angle Alpha of the grooves or projections increases by between 1* and 3* for each subsequent disc in direction of yarn movement.
 5. Device according to claim 1, characterized in that the ascending angle Alpha of the grooves or projections (27) is of the order of 30* + or - 5*.
 6. Device according to claim 1, characterized in that the discs consist of metal oxide ceramic material.
 7. Device according to claim 1, characterized in that the discs consist of aluminum and are provided at least on the rims with an oxide coating.
 8. Device according to claim 1, characterized by two carriers (3,4) each supporting a pair of adjacent shafts (6,7; 8,9), at least one of said carriers being arranged to pivot relatively to the other of said carriers.
 9. Device according to claim 8, characterized in that said one carrier is pivotable about the axis of one of the shafts supported by it. 